Clad metal body



Nov, 9, 1937.

F.- H. DRIGGS 2,098,282

CLAD METAL BODY Original Filed Feb. 6,` 1932 ATTORNE Patented Nov. 9, 1937 UNITED STATESV TENT GF'FIQE.

CLAD METAL BODY @riginal application February 6, 1932, Serial No. 591,300. Divided and this application April 20, 1935, Serial No. 17,469

'l Claims.

This application is a division of my application Serial No. 591,360 filed February 6, 1932 entitled Process for producing clad metals which issued November 5, 1935 as Patent No. 2,019,599.

This invention relates to clad metals and particularly is directed toy an X-ray anode having a target firmly imbedded in a material of high electrical and thermal conductivity.

X-ray anodes as previously employed in X-ray tubes were composed of a bar of copper having imbedded in one end thereof a target usually made from tungsten. Various processes. have been utilized in manufacturing such an X-ray anode. However, such prior processes, so far as I am aware, resulted in the formation of the anode in such a manner as to produce a small crystalline structurein the copper portion of the anode which crystalline structure was more or less disposed in a haphazard formation with no deiinite arrangement of the crystals.

By following the process set forth in the parent application above identied, a resultant product is attained in which not only is the tungsten target firmly imbedded in the copper body but in addition the crystals in the copper body are so disposed as to have their major axes extending in the direction of the longitudinal axis of the copper body. Furthermore, the crystals are of large size and the copper body is free from cuprous oxides and contains substantially no blow holes or pipes.

An object of my invention is to provide an element comprising a refractory metal and a relatively low melting point metal, the low melting point metal being substantially free from blow holes or pipes and containing no oxides, the union between the low-melting point metal and the refractory metal being tenacious `and of high thermal and electrical characteristics.

A further object of my invention is to provide a clad metal comprising tungsten and copper, the copper being in the form of preferentially orientated crystals and being free from blow holes or pipes and containing no cuprous oxide, the union between said tungsten and copper being mechanically strong and of high thermal and electrical conductivity characteristics.

Other objects and advantages of my invention will become apparent from the following specification taken in conjunction with the appended drawing in which the single iigure represents a longitudinal cross sectional view of an X-ray anode made in accordance with my invention.

Referring to the drawing, the anode comprises an elongated body portion I having embedded (Cl. Z50-35) in the end 2 thereof a button 3 consisting of a refractory material such as tungsten. As shown in dotted outlineinterposed between the copper body l and the tungsten button 3, is a copper surfacing material li which surfacing material as set forth in the parent application referred to above, is applied to the tungsten button 3 prior to securing the tungsten button to the body member I.

The copper body l is indicated as being free from any cuprous oxides or blow holes or pipes by reason of the absence of any cavities between the crystals 5 and because said crystals are shown as free from inclusions of any nature whatsoever; and also as indicated the crystals 5 are orientated sol that their longitudinal axes are substantially parallel to the longitudinal axis of the elongated' body I. The crystalline structure is obtained by following the process set forth in my parent application as identiiied above and depending upon the rapidity of cooling after casting. The crystalline structure is made of such size as may be found desirable. With the crystals orientated,

as indicated, the heat flow from the target I,

which becomes heated during usage, is not obstructed by any intervening crystal boundaries. It will thus be seen that a more efficient X-ray anode is obtained by reason of such orientation of the crystals. The process, as defined in my parent application, results in the elimination of any cuprous oxide or blow holes or pipes, and in the formation of an anode which is capable of more efliciently dissipating the heat from the tungsten target as the copper metal composing the anode is in the solid state.

A further feature which is obtained by reason of the orientation of the crystals `along the longitudinal axis of the anode is that the union between the low melting point metal and the refractory metal is exceedingly tenacious and of high thermal and electrical characteristics, it being apparent that where the crystals are disposed in a haphazard manner in the body of the anode, there will be more crystal junctures lying against the face of the tungsten button and the intervening copper body as provided upon the tungsten target before securing the main body I to the tungsten button 3.

As shown in the drawing, the elongated body 5 of copper is made up of four crystals 5 extending an appreciable distance along the major axis of the copper body I. It is apparent that by reason of this arrangement the heat in owing along a given copper crystal does not have any intervening crystal boundaries to pass through to impede its progress. If in the same length of crystal there were a great number of crystal boundaries, it is obvious that the ilow of heat would be considerably retarded.

Although my invention has been described with some particularity this is not to be taken by way of limitation but is to be considered as illustrating my invention, said invention being only limited in scope as determined by the prior art.

What is claimed is:

1. A clad metal comprising a body of metal having a relatively high melting point and another body of metal having a relatively low melting point, the quantity of said low melting point metal being materially in excess of that of said high melting point metal, said metals being contiguous, the joint at the place of contiguity being a iirm, tenacious, mechanical union of said two metals, said union having high thermal and electrical conductivity characteristics said low melting point metal being free from oxides and containing no voids and having the longitudinal axes of its crystal structure adjacent the relatively high melting point metal perpendicular to the greatest surface area thereof to increase the tenacity of the mechanical union therebetween.

2. A clad metal comprising a body of tungsten metal and a body of copper metal contiguous therewith, the quantity of said copper metal being in excess of that of said tungsten metal, the joint between said metals being a firm, tenacious mechanical union, said union having high thermal and electrical conductivity characteristics, said copper metal being free from oxides and containing no voids, said copper metal being in the form of compact crystals, the major axes of the crystals extending in the direction of the longitudinal axes thereof.

3. An X-ray anode comprising a body of refractory metal and a body of relatively low melting point metal of high thermal and electrical conductivity characteristics, said metals being contiguous, the joint between said metals being a rm, tenacious mechanical union of high thermal .and electrical conductivity characteristics with the crystal structure of said relatively low melting point metal adjacent the body of refractory metal having the longitudinal axes of the crystal structure perpendicular to the greater surface area of said refractory metal to increase the tenacity of the mechanical union therebetween, said low melting point metal being free from oxides and containing no voids.

4. An X-ray anode comprising a body of tungsten and a body of copper, the quantity of copper being in excess of that of said tungsten, said copper and tungsten being a rm, tenacious mechanical union, said union having high heat and thermal conductivity characteristics, said copper being free from oxides and containing no voids and having a crystal structure so oriented that the longitudinal axes thereof adjacent the tungsten body are perpendicular to the latter to increase the tenacity of the mechanical union therebetween.

5. An X-ray anode comprising a body of copper free from oxides and containing no voids, a

tungsten body embedded in one end of said copper body the union between the interfaces of said tungsten body and said copper body being a. rm, tenacious mechanical union having high thermal and electrical conductivity characteristics and said copper body having a crystal structure so oriented adjacent the body of tungsten that the longitudinal axes thereof are perpendicular to thatV of the body of tungsten to increase the tenacity of the mechanical union therebetween.

6. An X-ray anode comprising a body of refractory metal and a body of low-melting point metal, the volume of said low-melting point metal being much greater than that of said refractory metal body, said two bodies being rmly and tenaciously united to each other, said low melting point metal body being substantially free from pipes, said low melting point metal body being in the form of compact large crystals with the major axes of said crystals extending in the direction of the longitudinal axis of said low-melting point metal body.

7. An X-ray anode comprising a body of tungsten and a body of copper, the volume of copper being greater than that of said tungsten, said two bodies being iirmly and tenaciously united to each other, said copper body being substantially free from pipes, said copper body being in the form of compact large crystals, the major axes of said crystals extending in the direction of the longitudinal axis of said copper body.

FRANK H. DRIGGS. 

